<!DOCTYPE html>
<html lang="en" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>0.5pxLine</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
        .line {
            width: 100px;
            height: 1px;
            transform: scale(1, 0.5);
            background-color: red;
        }
    </style>
</head>
<body>
<div class="line"></div>
</body>
</html>